The essential task of our group is to provide material for use by the other groups. Two types of material are needed: tumor tissue from the patients when available (Wilm's tumors but also other malignancies appearing in the families under study, osteosarcomas, soft tissue sarcomas, breast carcinomas, etc.), and normal cells from all the members of said families. In order to have a continuous source of tumor material, fragments of Wilm's tumors or of other malignancies, obtained when surgery is performed on the patient, are transplanted subcutaneously in nude mice. If a positive take is obtained, the tumor is serially passaged in other nudes, expanded, viably frozen for further reference and supplied in any quantity requested to the other groups of our program. In order to have a continuous source of normal cells from which DNA, RNA and proteins can be extracted, blood samples obtained from patients and relatives are processed, their lymphocytes transformed by EBV and lymphoblastoid cell lines (LCL) obtained, propagated, expanded, viably frozen and supplied in any quantity requested to the other groups of our program. Fibroblasts are cultured from normal tissue biopsies obtained also from patients and relatives when feasible.